Smart Materials, Composites and Technical Textiles (Core) Flashcards
What is a modern material?
A material that has been developed through the invention of new or improved processes to improve the properties of the material, eg to make them stronger, faster, lighter and tougher.
What is graphene?
A single carbon layer material which is hypothetically 100 times stronger than steel, though we are yet to manufacture it in large enough quanitities to show this. In theory, it could provide body armour that is bulletproof, invisible and almost weightless.
What are liquid crystal displays (LCDs)?
Displays that use the light-modulating properties of liquid crystals to display an image. The liquid crystals are between a liquid and solid state. When charge is applied to each liquid crystal, the shape changes to either block light or let it through, meaning they require a backlight to work.
What are organic light-emitting diodes (OLEDs)?
An alternative to LCDs or LED screens which allows devices to be thinner and lighter. They are more expensive as each pixel is its own light, but they allow for thinner panels and better colour and contrast.
What are nanomaterials?
Tiny particles of 1 to 100 nanometres that can be used in thin films or coatings such as the oleophobic coatings on smartphone screens that repel greasy fingerprints, or hydrophobic materials that repel water.
What are breathable fabrics?
Fabrics designed to allow body moisture to evaporate away from the body, through the use of a breathable membrane laminated between layers of fabric, whilst still remaining waterproof. The membrane has microscopic holes, big enough to let body moisture through but too small for rain, and it is often used in tents and waterproof walking gear. Examples include Gore-Tex.
What are smart materials?
A modern material that exhibits a physical change in response to some external stimuli.
What are shape-memory alloys (SMAs)?
Metal alloys that can remember their shape when heated. These alloys have been utilised on spectacle frames that spring back to shape if they are squashed. Nitinol (nickel titanium) is a SMA used for braces, to pull the teeth into position.
What are thermochromic pigments?
Pigments that change colour when their temperature changes. These pigments can be mixed with paint or polymers to give the materials the same colour-changing properties as the pigment. Used in colour-changing mugs or bath items for children.
What are photochromic pigments?
Pigments that change their properties when exposed to ultraviolet (UV) light. Used in lenses in glasses, where the lenses are clear when worn inside a building, but become more like sunglasses when exposed to bright sunlight outside, protecting eyes from UV light and saving money on glasses.
What is electroluminescent wire?
A thin copper wire that is coated in phosphor, which glows brightly when current is applied to it. Used in fancy dress and decorative luminescent clothing, nightlights, waterproof displays, medical tool displays and billboards.
What is quantum-tunneling composite (QTC)?
An insulating rubber containing tiny particles of metal. When squashed, the metal particles meet and allow the flow of electrical current. As a result, QTC is an insulator when resting and a conductor when pressure is appied. Used in outdoor applications where water might otherwise damager tiny microswitches, in power tools to give variable speed controls, in touch-sensitive pads and even in clothing to control smartphones and portable music players.
What are self-healing materials?
Materials with the ability to repair themselves, which can extend the lifespan of the products they are used in. These include polymers that can heal knife cuts in themselves, metals that resist corrosion and concrete that can heal when cracked.
What are composite materials?
Materials made up of other different materials to combine and improve their properties.
What is polymorph?
A polymer that becomes malleable when heated to about 62°C. When it cools down it becomes hard enough to drill and cut, making it perfect for modelling as it can be reheated and formed again. Used in creating ergonomic handles.
